Answer architecture round 1: a code span opening a line spells as CommonMark, the slot refuses a null character, every generated document emits

corpus/README.md

@@ -16,7 +16,7 @@ One directory per contract kind:
   is the suite; `refusals.json` pins each refusing example to its error `code`; `exceptions.json`
   pins each known divergence by `check`, `example`, `kind` and the exact `divergence`, with a
   `reason`. `kind` is `mark-model` (the permanent count divergence from ADF's mark-per-text-node
-  model), `unspellable` (parses but the flavour has no spelling) or `pending` (a parser gap).
+  model) or `pending` (a parser gap).
 
 JSON is two-space indent, keys sorted, and a document read back must deep-equal the fixture's
 (`docs/decisions.md` §Equality is deep). `spec.json` is the vendored, upstream machine-readable

corpus/round-trip/block-nodes/code-block-carriage-return.json

@@ -0,0 +1,15 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "text": "a\r\nb",
+          "type": "text"
+        }
+      ],
+      "type": "codeBlock"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/block-nodes/code-block-carriage-return.md

@@ -0,0 +1,10 @@
+```adf:codeBlock
+{
+  "content": [
+    {
+      "text": "a\r\nb",
+      "type": "text"
+    }
+  ]
+}
+```

corpus/round-trip/commonmark-subset/code-span-line-start.json

@@ -0,0 +1,20 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "marks": [
+            {
+              "type": "code"
+            }
+          ],
+          "text": "``",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/commonmark-subset/code-span-line-start.md

@@ -0,0 +1 @@
+``` `` ```

corpus/round-trip/inline-nodes/text-carriage-return-null.json

@@ -0,0 +1,43 @@
+{
+  "content": [
+    {
+      "content": [
+        {
+          "text": "a\r\nb\u0000c",
+          "type": "text"
+        },
+        {
+          "marks": [
+            {
+              "attrs": {
+                "href": "https://example.com/",
+                "title": "t\u0000"
+              },
+              "type": "link"
+            }
+          ],
+          "text": "link",
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    },
+    {
+      "content": [
+        {
+          "attrs": {
+            "color": "neutral",
+            "text": "a\nb"
+          },
+          "type": "status"
+        },
+        {
+          "type": "text"
+        }
+      ],
+      "type": "paragraph"
+    }
+  ],
+  "type": "doc",
+  "version": 1
+}

corpus/round-trip/inline-nodes/text-carriage-return-null.md

@@ -0,0 +1,3 @@
+a
!adf:text{text="\n"}b!adf:text{text="\u0000"}c!adf:link[link]{href="https://example.com/" title="t\u0000"}
+
+!adf:carry{json="{\"attrs\":{\"color\":\"neutral\",\"text\":\"a\\nb\"},\"type\":\"status\"}"}!adf:carry{json="{\"type\":\"text\"}"}